JP2015515017A - Jointing curved acoustic honeycombs - Google Patents

Abstract

The honeycomb sections are joined together using a seam composed of an adhesive carried by a honeycomb seam support or a connected segment seam support. These seams are particularly useful when splicing curved honeycomb sections containing acoustic bulkheads together. The curved acoustic honeycomb sections are spliced or seamed together to form engine nacelles and other acoustic damping structures.

Description

  The present invention generally relates to forming seamed acoustic honeycombs by connecting together the sides of two or more acoustic honeycomb sections. More particularly, the present invention provides improved seams between acoustic honeycomb sections, particularly when a plurality of honeycombs are joined together to form a contoured or curved acoustic honeycomb structure. It is intended to provide.

  The present invention is particularly useful for integral seam joining or seaming of curved acoustic honeycomb sections where engine nacelles and other acoustic damping structures are formed by seam joining together.

  It is widely accepted that the best way to deal with excess noise generated by a particular source is to handle the noise at the source. This is typically accomplished by adding an acoustic processing device to the structure located at the noise source. One particularly problematic noise source is the jet engine used to propel the aircraft. Sound processing devices are typically incorporated into engine intakes, nacelles, and exhaust structures. These acoustic processing devices include an acoustic resonator containing a relatively thin acoustic material or acoustic grid having a number of holes that generate acoustic impedance to the acoustic energy generated by the engine. The fundamental problem facing engineers is how to add these thin and flexible acoustic materials to the structural elements of the jet engine and surrounding nacelles to achieve the desired noise attenuation. It is.

  Honeycombs have become common materials for use in aircraft and aerospace aircraft because they are relatively strong and lightweight and each honeycomb cell can be used as an acoustic resonator. For acoustic applications, the goal is to somehow incorporate a thin acoustic material into the honeycomb structure so that the honeycomb cells are closed or covered. Closing the cell with acoustic material creates the acoustic impedance that underlies the resonator.

  Forming an acoustic honeycomb in the complex curved image structure required for engine nacelles is a major design consideration. It is very difficult to form a single honeycomb in an engine nacelle without significantly changing the honeycomb and its acoustic properties. Thus, typically, multiple sections of curved or slightly curved acoustic honeycomb sections are spliced together to form a cylindrical nacelle structure.

  The side of the honeycomb that is spliced together is made up of a number of protruding cell walls, typically referred to as “dog ears”. The protruding cell walls that make up the dog-ear have ends, which have a relatively small surface area for joining the two honeycomb sections together. Furthermore, it is very difficult to position the honeycomb sections so that the ends of the dog-ears of the opposing honeycomb sections are aligned and close enough to join.

  The aforementioned joining / sealing problem has typically been solved by filling the seam line and the partial cells adjacent to the seam line with an adhesive. This adhesive is used to achieve a solid (solid) and tight bond by completely filling all the spaces along the seam line. For aerospace applications, this adhesive is typically a foam-type adhesive to keep the seam weight to a minimum. One advantage of filling seam lines and surrounding partial cells with adhesive is that the surface area of the honeycomb that can be used for bonding is much greater than the surface area provided by the end of the dog ear. . Strong bonding is achieved by the relatively large surface area of the honeycomb that forms the seam by interaction with the adhesive. In addition, foam type adhesives can be used to join curved and / or serpentine honeycomb sides together. Since joining is accomplished by simply filling the seam line with adhesive, the shape and orientation of the dog ears and partial cells along the seam line will change without affecting the overall performance of the seam. It becomes possible.

  The use of an adhesive seam line has disadvantages in practice. For example, the acoustic properties of honeycomb cells filled with adhesive are significantly changed or lost. Solid adhesive seams tend to be wide and relatively heavy, which is undesirable for aerospace applications where weight limitations are an important design consideration. Also, the strength of the seam can vary depending on the dog ear orientation on either side of the seam line. In addition, the relatively wide adhesive seam tends to stiffen, limiting the ability to bend or otherwise shape the entire bonded honeycomb into a curved structure such as an engine nacelle. obtain.

US Pat. No. 7,434,659 US Pat. No. 7,510,052 US Pat. No. 7,854,298 US Patent Application No. 13 / 227,775 U.S. Patent Application No. 13 / 274,484

  Provide a method for seaming or seaming honeycombs together that provides the strength of joint strength achieved by the solid adhesive seam described above and avoids drawbacks related to acoustic properties, seam weight, and seam stiffness. It is desirable.

  In accordance with the present invention, it has been found that a narrow and high strength seam can be provided between honeycomb sections when a flexible adhesive support is used in combination with an adhesive. This supported seam is much thinner than previous foam-type adhesive seams and can be used whether or not the protruding ends of the honeycomb are aligned along the seam. This thinner seam provided by the present invention minimizes any interference to the acoustic properties of the seamed honeycomb. Furthermore, the supported seam of the present invention is flexible and can be used to join curved honeycombs together. It is also possible to form a serpentine seam between the honeycomb sections.

  The seamed honeycomb of the present invention comprises at least a first honeycomb section and a second honeycomb section, which are joined together along their sides. Each honeycomb section has a first edge and a second edge. Each honeycomb section comprises a plurality of walls that extend between their first and second edges. These walls define a plurality of honeycomb cells, each honeycomb cell having a cross-sectional area measured perpendicular to the honeycomb wall and a first edge and a second edge of the honeycomb. A depth defined by the distance between. Each honeycomb section has a plurality of projecting honeycomb walls each having a wall end having a thickness and a length extending between the first and second edges of each honeycomb section. With at least one side.

  As a feature of the present invention, two honeycomb sections are joined together using a seam disposed between the sides of the two honeycomb sections. The seam has a depth that extends between the first and second edges of the honeycomb section, a thickness, and a seam length that extends along the sides of the honeycomb section. The seam includes an adhesive for bonding to the end of the protruding honeycomb wall and an adhesive support. It has been found that the use of an adhesive support provides the desired integral joining of the honeycomb sections without filling the cells with adhesive along the seam.

  As a unique feature of the present invention, the adhesive support is a relatively thin honeycomb seam support. The honeycomb seam support comprises a first edge disposed adjacent to the side of one honeycomb section and a second edge disposed adjacent to the side of the other honeycomb section. . The honeycomb seam support includes a plurality of walls extending between the first edge and the second edge of the honeycomb seam support. These walls form a plurality of seam cells positioned perpendicular to the cells of the honeycomb section. By placing the adhesive in the seam cell, the adhesive joins both the seam cell and the wall protruding from the side of the honeycomb section.

  As another characteristic feature of the present invention, the adhesive support includes a first end, a second end, a first side disposed adjacent to the first honeycomb side, and A connected segment seam support comprising a plurality of seam support members, each having a second side disposed adjacent to the second honeycomb side. The adhesive is disposed on both sides of the seam support member so that the adhesive joins both the seam support member and the protruding dog ear of the honeycomb section. To provide flexibility to a seam, a flexible joint is provided that connects a first end of one seam support member to a second end of another seam support member. This type of chain connection configuration has proven effective in achieving both high strength honeycomb seams and flexible honeycomb seams.

  The present invention relates to an entire seam and seamed honeycomb structure. The invention also relates to a method for seaming honeycomb sections together. Also included is a method for shaping or forming the honeycomb section into the desired structure before and / or after the sections are seamed together. The seam of the present invention is particularly useful when seaming acoustic honeycomb sections together to form a curved acoustic honeycomb structure such as that found in jet engine nacelles.

  The foregoing and numerous other features and attendant advantages of the present invention will become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.

Fig. 2 shows two honeycomb sections spliced or joined together according to the present invention. In this embodiment, the ends of the honeycomb cell wall (dog ear) protruding along the side of the honeycomb section are aligned with each other at the seam. FIG. 4 is a view showing an embodiment of the present invention in which two honeycomb sections are joined together so that ends of protruding honeycomb cell walls are not aligned with each other by seams. FIG. 6 is a view showing a part of another seam in which protruding honeycomb cell walls located on each side of the seam are not aligned with each other. FIG. 4 is an exploded view showing two curved honeycomb sections before being spliced together with a honeycomb seam according to the present invention. FIG. 4 shows how a honeycomb seam support is cut from a larger honeycomb structure. FIG. 4 shows a process in which a honeycomb seam structure is curved and then coated with an adhesive. FIG. 7 is a side view of the honeycomb seam support to which an adhesive has been applied, showing the cross section of FIG. 6. FIG. 3 illustrates an exemplary connected segment seam support according to the present invention. FIG. 9 is a cross-sectional view of the connecting segment seam support shown in FIG. 8 showing details of the flexible joint between the two connecting segments. FIG. 3 shows a partial acoustic panel before assembly, where the panel comprises three honeycomb sections and two seams. Fig. 3 illustrates an exemplary honeycomb configuration that can be spliced together and / or used as a honeycomb seam support according to the present invention. FIG. 4 shows a curved acoustic panel comprising acoustic honeycomb sections seamed or seamed together according to the present invention. FIG. 4 shows an alternative exemplary honeycomb seam support according to the present invention. This seam support is shown next to the end of the dog ear to show the relative size of the honeycomb cells in the seam support relative to the end of the dog ear. FIG. 4 shows a further alternative exemplary honeycomb seam support according to the present invention. This seam support is shown next to the end of the dog ear to show the relative size of the honeycomb cells of the seam support relative to the end of the dog ear. FIG. 2 is a detailed view of a wall (dog ear) protruding from one side of the honeycomb section shown in FIG. 1.

  The present invention can be used to seam bond, seam, or join together a variety of complex honeycomb types and shapes. The honeycomb can be made of any appropriate material as long as it is a material that can be easily bonded with an adhesive. The cutting edge (dog ear) of the honeycomb should be straight (90 ° with respect to the surface) without burrs, and the acoustic partition walls should also be free of burrs and straight Don't be. The seam according to the present invention is particularly useful when seaming acoustic honeycomb sections together to form a curved structure such as a nacelle for a jet engine. The following detailed description is mainly focused on the integral seaming of acoustic honeycombs. The described seam can also be used to splice various other types of acoustic and non-acoustic honeycomb sections together where a high strength, light weight and relatively thin seam is desired. Is understood.

  A seamed acoustic honeycomb according to the present invention is shown generally at 10 in FIG. The seam bonded honeycomb 10 comprises a first honeycomb section 12 and a second honeycomb section 14. The honeycomb sections 12 and 14 can be made from any of the conventional materials used in making honeycomb panels, including metals, ceramics, and composite materials. Exemplary metals include aluminum and aluminum alloys. Exemplary composite materials include fiberglass, nomex, and various combinations of graphite or ceramic fibers and a suitable matrix resin. Exemplary matrix resins include thermosetting resins or thermoplastic resins, but the thermosetting resins may or may not be toughened with thermoplastic resins.

  The first honeycomb section 12 has a first edge 16 to be placed closest to the noise source and a second edge 18. The first honeycomb section 12 comprises a wall 20 that extends between two edges 16 and 18 and defines a plurality of cells 22. Each cell 22 has a depth (or also called core thickness) equal to the distance between the two edges 16 and 18. Each cell 22 has a cross-sectional area measured perpendicular to the cell wall 20. The first honeycomb section 12 has a first honeycomb side 24 with a plurality of protruding honeycomb walls or dog ears 26, one of which is shown in detail in FIG. It is. Each protruding wall 26 has a wall end 28 having a length (L) extending between the first edge 16 and the second edge 18. The wall end 28 has a width or a thickness (T).

  The second honeycomb section 14 also has a first edge 30 and a second edge 32. The second honeycomb section 14 includes a wall 34 that extends between the two edges 30 and 32 and defines a plurality of cells 36. Each cell 36 has a depth equal to the distance between the two edges 30 and 32. Each cell 36 has a cross-sectional area measured perpendicular to the cell wall 34. The second honeycomb section 14 has a second honeycomb side 38 with a plurality of protruding honeycomb walls 40. Each protruding wall 40 also has a wall end that is shaped identically to the wall end 28 of the honeycomb section 12, as shown in detail in FIG. Thus, each protruding wall 40 also has a wall end having a length (L) and a width or thickness (T) extending between the first edge 30 and the second edge 32. Have

  As shown in FIG. 1, the sides 24 and 38 of each honeycomb section 12 and 14 are spliced together by a seam 42 composed of an adhesive and an adhesive support according to the present invention. The seam 42 has a depth that extends between the first edges (16 and 30) of the honeycomb sections (12 and 14) and the second edges (18 and 32) of the honeycomb sections (12 and 14). Have The seam 42 also has a thickness and a seam length that extends along the first honeycomb side 24 and the second honeycomb side 38. The two sections of the honeycomb shown in FIG. 1 are oriented so that the ends of the protruding honeycomb walls 26 and 40 are aligned at the seam 42.

  As one feature of the present invention, as shown in FIG. 1, the protruding honeycomb wall (dog ear) does not need to be aligned across the seam 42. An alternative exemplary seamed honeycomb is shown in FIG. 2, where the protruding honeycomb walls are not aligned across the adhesive seam. In FIG. 2, the sides of the first honeycomb section 44 and the second honeycomb section 46 are joined together via a supported adhesive seam 48 according to the present invention. The ends of the projecting honeycomb walls 50 and 52 arranged on both sides of the seam 48 are not aligned. It has been found that the supported adhesive seam 48 has sufficient strength to eliminate the need to align the cell walls protruding at the seam joint.

  Another unaligned seamed honeycomb is shown in FIG. 3, where different configurations of unregistered dog ears are illustrated. In FIG. 3, the sides of the first honeycomb section 54 and the second honeycomb section 56 are joined together via a supported adhesive seam 58 according to the present invention. The ends of the projecting honeycomb wall portions 60 and 62 located on both sides of the seam 58 are not aligned. It has also been found that the supported adhesive seam 58 has sufficient strength to make it unnecessary to align the cell walls protruding at the seam joint.

  The supported adhesive seam of the present invention is particularly well suited for integral seaming of acoustic honeycomb sections. These seams are relatively narrow and do not significantly interfere with the acoustic properties of the acoustic cells located along the seam. Acoustic honeycombs comprise one or more partition walls arranged in most if not all honeycomb cells. Any type of septum may be used, but the septum of the type described in detail in US Pat. No. 7,434,659, US Pat. No. 7,510,052, and US Pat. No. 7,854,298. Is preferred. These types of partition walls are relatively flexible and are used when forming a honeycomb in a curved (non-planar) structure such as a honeycomb section that is spliced together to form a jet engine nacelle. These types of partition walls are preferred in order to maintain sound absorption characteristics.

  A septum cap is illustrated at 64 in FIG. 1 and 66 and 68 in FIGS. 2 and 3, respectively. Any of the acoustic materials typically used in acoustic honeycombs can be used to form the septum cap. The acoustic material is typically provided as a relatively thin sheet that is a perforated, porous, or coarse mesh fabric designed to provide noise attenuation. Perforated sheets and porous sheets of various materials (metal, ceramic, and plastic) can be used. In one preferred embodiment, the acoustic material is an open mesh fabric woven from monofilament fibers. These fibers can be composed of glass, carbon, ceramic, or polymer. Polyamide, polyester, polyethylene chlorotrifluoroethylene (ECTFE), ethylenetetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyfluoroethylenepropylene (FEP), polyetheretherketone (PEEK) Monofilament polymer fibers made from polyamide 6 (nylon, 6PA6) and polyamide 12 (nylon 12, PA12) are just a few examples. A coarse mesh fabric made from PEEK is preferred for high temperature applications. Coarse mesh acoustic fabrics are available from a variety of commercial sources. For example, a coarse mesh acoustic fabric sheet is available from SEFAR America Inc. (Buffalo Division Headquarters 111 Calamette Street Dep., NY 14043), commercially available under the trade names SEFARPETEX, SEFAR NITEX, and SEFAR PEEKTEX.

  Also, a solid sheet of acoustic material can be used to form the septum cap. In this example, the perforations are formed in the solid sheet material either before or after the septum cap is placed in the honeycomb cell. Although the types of metals, ceramics, and plastics identified above can be used to make perforated septa, the acoustic material is PEEK or a similar chemically resistant polymer material suitable for high temperature applications And preferred. PEEK sheets or films are commercially available from a number of sources, such as Victrex USA (Greenville, South Carolina), which produces PEEK sheets under the trade name VICTREX (R) PEEK (TM) polymer. Further details regarding partition caps and their use in acoustic honeycombs are presented in US patent application 13 / 227,775 and US patent application 13 / 279,484.

  The seam of the present invention includes an adhesive and a support for the adhesive. The adhesive can be any suitable adhesive typically used in connection with honeycomb panel manufacturing. Also, the same adhesive that is used to join the partition cap to the honeycomb is generally suitable for use as a seam adhesive. Preferred adhesives include those that are stable at elevated temperatures (300-400 ° F.). Exemplary adhesives include epoxy resins, acrylic resins, phenols, cyanoacrylates, bismaleimides, polyamideimides, and polyimides. Particularly preferred for polyamideimide adhesives.

  The support for the adhesive should be a structure that is relatively thin and has sufficient strength to give the seam additional strength beyond that achieved by the adhesive alone. Preferably, the support is sufficiently flexible so that it can be bent or bent to align the sides of the curved honeycomb sections seamed together. It is important that the entire seam be as narrow or thin as possible to minimize interference with the acoustic properties of the honeycomb cell.

  The exemplary seams 42, 48, and 58 shown in FIGS. 1, 2, and 3 comprise a honeycomb seam support filled with a seam adhesive. In FIG. 4, the exemplary seam 42 is illustrated in a position prior to being joined to the curved honeycomb sections 12 and 14. The seam 42 includes a honeycomb support structure 70 and an adhesive 72. The honeycomb seam support 70 includes a first edge 76 disposed adjacent to the side of the honeycomb section 12 and a second edge 78 disposed adjacent to the side of the honeycomb section 14. Can be seen as having. The wall of the honeycomb seam support 70 extends between the first edge 76 and the second edge 78 to define a plurality of seam cells 80. Each of the seam cells has a cross-sectional area measured perpendicular to the honeycomb walls. The thickness (T) of the honeycomb seam support is defined by the distance between the first edge 76 and the second edge 78 of the honeycomb seam support 70.

  The honeycomb seam support 70 is preferably made by cutting or thinly cutting a honeycomb layer from a larger honeycomb structure 74 as shown in FIG. The honeycomb slice 70a (FIG. 4) used to form the seam support 70 has an identification number corresponding to that described above, but comprises the honeycomb slice 70a and honeycomb cells filled with an adhesive. In order to identify the final seam support 70, “a” is given to each number.

  As shown in FIG. 6, the honeycomb slice 70a is formed into a curved shape 70b that matches the curve of the honeycomb sections that will be seam bonded together. This curved honeycomb slice 70b is then filled with adhesive to create a final seam 42 for joining to the two honeycomb sections. A side cross-sectional view of a seam support 70 filled with adhesive 72 is shown in FIG. The seam support 70 is preferably between 0.01 inch and 0.15 inch thick. The adhesive protrudes outward beyond the seam support 70 as indicated at 72 in FIG. The adhesive typically protrudes outward from each side of the seam support in the range of 0.001 inch to 0.02 inch.

  The honeycomb seam support is preferably applied with the desired adhesive so that substantially all the cells in the structure are filled with this adhesive and the edges of the seam support structure are covered. Adhesive may be applied to some edges of the honeycomb seam support as desired to ensure complete coverage of the ends of the dog ears that are placed on the honeycomb sections to be joined together. It may extend beyond. However, excessive application to the honeycomb seam support should be avoided as it results in waste of adhesive and can result in unintentional plugging of cells adjacent to the seam due to excess adhesive. .

  The viscosity of the adhesive and the relative cell size of the seam support structure should be such that the adhesive is stabilized and does not flow out of the structure. If desired, release paper may be placed on both sides of the adhesive-filled support structure to help hold the adhesive in place. The release paper is removed just before joining the seam to the honeycomb section.

  The cross-sectional configuration or cross-sectional shape of the honeycomb cells forming the honeycomb seam support depends on the dimensions and other characteristics of the honeycomb sections to be spliced, the size of the seam and the desired flexibility. Can change. Conventional hexagonal honeycomb cell cross sections, such as the cell 80 shown in the seam supports 70 and 70a, are suitable for many applications. A variety of other cross-sectional configurations may be used as desired. For example, a honeycomb seam support structure is shown at 110 in FIG. 12, but here the cross-sectional shape of the honeycomb seam support has been changed from a typical hexagonal shape.

  A seam support structure 110 is shown next to the dog ear 26 to indicate the preferred size of the honeycomb seam support cell relative to the length of the dog ear. As shown, the cells of the honeycomb seam support 110 are sized such that eight cells are present for joining along the length (L) of the dog ear. As an example, a dog ear having a length of 2.54 cm (1 inch) requires a seam support 110 with cells having a height of 1/8 inch. A seam support cell having this type of size correlation with the dog-ear end wall is preferred because it provides an optimal combination of seam strength and adhesive retention.

  Another exemplary honeycomb seam support structure is shown at 111 in FIG. The cross-sectional shape of the seam support 111 is useful in situations where a higher degree of flexibility is desired in the seam support. Other cell cross-sectional shapes may be used to achieve specific design goals for seam shape, size, and desired strength. A seam support structure 111 is also shown next to the dog ear 26 to show the preferred size of the honeycomb seam support cell relative to the length of the dog ear. The seam support 111 is also sized so that eight cells are present for joining along the length of the dog ear. Preferably, if the honeycomb is 1/2 inch to 2 inches thick, 5-20 cells are joined along the length of the dog ear. For exist.

  The seam according to the present invention simply sandwiches an adhesive-coated honeycomb seam support between two formed acoustic honeycomb sections that are to be spliced together, and pressure is applied to the seam and honeycomb section. Formed by ensuring uniform contact between both sides. Heat is applied to cure the adhesive and form the final seam.

  The honeycomb structured seam of the present invention can be used to join planar honeycomb sections together. However, the honeycomb-structured seam is particularly useful when seam-bonding acoustic honeycomb sections curved in the L / D plane together as shown in FIG. The honeycomb sections can be spliced together and then curved to form a curved honeycomb. However, this requires that the adhesive and honeycomb support structure combination be such that the resulting seam is flexible enough to be bent into the desired curved shape. To do. Preferably, the seam is applied to the honeycomb sections after the two honeycomb sections are formed into the desired curved shape. Since the honeycomb seam support structure is much more flexible before the adhesive is solidified or cured, it is preferable to seam the pre-curved honeycomb sections.

  The honeycomb sections that can be spliced together using the seam of the present invention can be varied in cell cross-sectional area, wall thickness, and depth. A typical acoustic honeycomb section has cells having a cross-sectional area in the range of 32.26 square mm to 645.16 square mm (0.05 square inches to 1 square inch) or greater. The wall thickness of the honeycomb material typically ranges from 0.0254 mm to 1.27 mm (0.001 to 0.050 inches). The depth (core thickness) of the cell is in the range of 6.35 mm to 76.2 mm (0.25 to 3 inches) or more. Exemplary honeycomb sections have a cross-sectional area of about 64.52 to 322.58 square millimeters (about 0.1 to 0.5 square inches) and about 0.635 to 1.27 millimeters (0.025 to 0.005). (05 inches) and a hexagonal cell with a depth of about 2.54 to 5.08 mm (1.0 to 2.0 inches).

  The protruding wall end for a honeycomb having the above size range has a length (L) of 6.35 mm to 76.2 mm (0.25 to 3 inches) or more, which is the depth of the honeycomb core. Matches. The thickness (T) of the protruding wall corresponding to the thickness of the honeycomb material is 0.0254 mm to 1.27 mm (0.001 inch to 0.050 inch). The size of the seam cells is selected so that the plurality of seam cells contact the wall edges along their lengths as shown in FIGS. Typical seam cell sizes range from 1.57 to 4.75 mm (0.062 to 0.187 inches). This allows greater cell edge contact for the dog-ear, and the smaller cells help stabilize the cell's adhesive film.

  The relative size of the seam cell relative to the length of the wall edge can be varied to achieve the desired seam design goals. In general, smaller seam cells provide a greater surface area and seam cell joint location along the wall edge length to create a relatively strong and rigid seam.

  A portion of an alternative adhesive support is shown at 82 in FIGS. Adhesive support 82 is a connected segment seam support comprised of seam support members 84, 86, and 88. Only three segments of the seam support are shown for illustrative purposes. A typical seam is composed of a number of connecting support members. Each support member has a first end 90 and a second end 92. Further, the support member includes a first side portion 94 disposed adjacent to the side portion of one honeycomb section, and a second side portion disposed adjacent to the side portion of the other honeycomb section. 96. A flexible joint 98 is provided to connect the first end 90 of one seam support member to the second end 92 of another seam support member. Many different types of flexible joints are possible. Joints that add a minimum amount of weight are preferred. A preferred flexible joint is shown in FIG. 7, where the seam support member 88 has a circular flange 100 formed in the opening 102 of the seam support member 86 to hinge the two support members together. . This type of flexible connection is preferred because it provides very low, if any, weight to the seam support.

  The seam adhesive is placed on both sides of the adhesive support 82 and the supported adhesive is then used to seam the honeycomb sections together, similar to the honeycomb seam supported adhesive described above. Is done. The amount of adhesive should be limited to the amount necessary to form some adhesive fillet in the dog ear to form a strong joint. The use of excess adhesive should be avoided as it increases the weight of the seam. In some situations, it may be desirable to apply the adhesive only to the portion of the adhesive support that contacts the dog ear. However, this may not be practical when the honeycomb sides include a large number of dog ears that are separated from each other by a short distance. In these situations, it is preferred that the side of the adhesive support member is substantially covered with the adhesive layer.

  The material used to make the adhesive support 82 can be any of the same materials used to make the honeycomb. This material should be thin enough to be able to bend to provide some flexibility to the seam in the T direction. The adhesive support material is preferably the same as that used to make the honeycomb section. The thickness of this material can be varied and is preferably as thin as possible while still increasing the seam strength. The preferred exemplary material thickness matches the thickness of the honeycomb wall that will be spliced together. An exemplary material for an acoustic honeycomb is aluminum or composite material having a thickness of 0.0254 to 0.254 mm (0.001 to 0.010 inches). The preferred thickness of adhesive on each side of the connecting seam support should be about 0.054 to 1.75 inches (0.054 to 1.91 mm) on each side.

  An exemplary seamed acoustic honeycomb is shown in FIG. 10 where three honeycomb sections 104, 106, and 108 are seamed together along two seams 130 and 132. Each of these honeycomb sections includes a partition cap 134. The seamed honeycomb section is sandwiched between a solid panel or solid surface sheet 136 and a perforated panel or perforated surface sheet 138. These face sheets are bonded to the edges of the joined honeycombs using a conventional panel fabrication process.

  A section of curved seamed honeycomb acoustic panels or nacelles is shown at 140 in FIG. A jet engine center or other noise source is shown schematically at 142. The curved acoustic panel includes an outer solid surface sheet 144 and an inner perforated surface sheet 146. Various honeycomb sections are spliced together by vertically oriented seams 148, 150, and 152. Seam 154 extends horizontally between seams 148 and 150. The seamed curved acoustic honeycomb sections are 0.75 to 1.5 inches thick, and these seams are 0.508 to 5.08 mm (. 02 inches to 0.20 inches). As a feature of the present invention, a relatively thin seam made using a combination of an adhesive and an adhesive support provides a suitable integral seam connection between the honeycomb sections, as well as an acoustic panel or nacelle. Has been found to minimize the impact on the acoustic properties of

  While exemplary embodiments of the present invention have been described in this manner, those skilled in the art will recognize that the present disclosure includes only exemplary ones, and that various other alternatives, adaptations, and Note that changes can be made. Accordingly, the invention is not limited by the above-described embodiments, but only by the scope of the following claims.

Claims (20)

A first honeycomb section comprising a first edge and a second edge, wherein the first honeycomb section includes a plurality of sections extending between the first edge and the second edge; Further comprising a wall, wherein the wall defines a plurality of honeycomb cells, each honeycomb cell having a cross-sectional area measured perpendicular to the wall, and the first edge and the A depth defined by a distance between the second edge and the first honeycomb section extending between the first edge and the second edge; A first honeycomb section further comprising a first honeycomb side portion comprising a plurality of protruding honeycomb wall portions each having a wall end portion having a thickness;
A second honeycomb section comprising a first edge and a second edge, wherein the second honeycomb section is a plurality of sections extending between the first edge and the second edge. Further comprising a wall, wherein the wall defines a plurality of honeycomb cells, each honeycomb cell having a cross-sectional area measured perpendicular to the wall, and the first edge and the A depth defined by a distance between the second edge and the second honeycomb section extending between the first edge and the second edge; A second honeycomb section further comprising a second honeycomb side portion comprising a plurality of protruding honeycomb wall portions each having a wall end portion having a thickness;
A seam disposed between the first honeycomb section and the second honeycomb section to adhesively bond the first honeycomb side to the second honeycomb side; The seam extends in depth, thickness, and first side between the first and second edges of the first and second honeycomb sections. And a seam length extending along the second side, and the seam is joined to the wall end of the first honeycomb side and the second honeycomb side. And a seam comprising a support for the adhesive.   The support is a honeycomb seam support, and the honeycomb seam support is adjacent to the first edge and the second honeycomb side disposed adjacent to the first honeycomb side. A second edge, wherein the honeycomb seam support further comprises a plurality of walls extending between the first edge and the second edge of the honeycomb seam support; The section defines a plurality of seam cells, each seam cell having a cross-sectional area measured perpendicular to the wall and between the first edge and the second edge. The seamed honeycomb of claim 1, having a thickness defined by a distance, and wherein the adhesive is disposed within the seam cell. The support is
A first end, a second end, a first side disposed adjacent to the first honeycomb side, and a second disposed adjacent to the second honeycomb side. A plurality of seam support members each having a side, wherein the adhesive is disposed on both the first side and the second side of the seam support member; A plurality of seam support members;
A connecting segment seam support comprising a flexible joint for connecting the first end of one seam support member to the second end of another seam support member; The seamed honeycomb of claim 1.   The honeycomb seam support includes an upper edge disposed between the first edges of the first honeycomb section and the second honeycomb section, the first honeycomb section, and the first honeycomb section. A lower edge disposed between the second edges of two honeycomb sections, the upper edge and / or the lower edge of the honeycomb seam support being curved. The seamed honeycomb of claim 1.   The seamed honeycomb of claim 4, wherein the first honeycomb side and the second honeycomb side are curved so that the seam forms a bow shape.   The seamed honeycomb of claim 1, wherein the first honeycomb section and the second honeycomb section comprise acoustic partition walls disposed within the honeycomb cells.   The seamed honeycomb of claim 6, wherein the partition comprises a partition cap that is adhesively bonded to the wall of the honeycomb cell.   The seamed honeycomb of claim 1, wherein the thickness of the seam is between 0.01 inch and 0.20 inch.   An engine nacelle comprising the seamed honeycomb of claim 6.   A jet engine comprising the engine nacelle according to claim 9. A method for splicing honeycomb sections together,
Providing a first honeycomb section comprising a first edge and a second edge, the first honeycomb section extending between the first edge and the second edge; A plurality of existing wall portions, wherein the wall portions define a plurality of honeycomb cells, each honeycomb cell having a cross-sectional area measured perpendicular to the wall portions, and the first A depth defined by a distance between the first edge and the second edge, wherein the first honeycomb section extends between the first edge and the second edge. Further comprising a first honeycomb side portion comprising a plurality of protruding honeycomb wall portions each comprising a wall end portion having a length and a thickness;
Providing a second honeycomb section comprising a first edge and a second edge, wherein the second honeycomb section extends between the first edge and the second edge. A plurality of existing wall portions, wherein the wall portions define a plurality of honeycomb cells, each honeycomb cell having a cross-sectional area measured perpendicular to the wall portions, and the first Having a depth defined by the distance between the second edge and the second edge, the second honeycomb section extending between the first edge and the second edge Further comprising a second honeycomb side portion comprising a plurality of protruding honeycomb wall portions each comprising a wall end portion having a length and a thickness;
Forming a seam disposed between the first honeycomb section and the second honeycomb section to adhesively bond the first honeycomb side to the second honeycomb side. Wherein the seam extends a depth, thickness between the first edge and the second edge of the first honeycomb section and the second honeycomb section; and A seam length extending along the first side and the second side, wherein the seam is the end of the wall of the first honeycomb side and the second honeycomb side; An adhesive for bonding to the substrate and a support for the adhesive.   The support is a honeycomb seam support, and the honeycomb seam support is adjacent to the first edge and the second honeycomb side disposed adjacent to the first honeycomb side. A second edge, wherein the honeycomb seam support further comprises a plurality of walls extending between the first edge and the second edge of the honeycomb seam support; The section defines a plurality of seam cells, each seam cell having a cross-sectional area measured perpendicular to the wall and between the first edge and the second edge. The method for splicing together honeycomb sections according to claim 11, having a thickness defined by a distance, and wherein the adhesive is disposed within the seam cell. The support is
A first end, a second end, a first side disposed adjacent to the first honeycomb side, and a second disposed adjacent to the second honeycomb side. A plurality of seam support members each having a side, wherein the adhesive is disposed on both the first side and the second side of the seam support member; A plurality of seam support members;
A connecting segment seam support comprising a flexible joint for connecting the first end of one seam support member to the second end of another seam support member; A method for splicing together honeycomb sections according to claim 11.   The honeycomb seam support includes an upper edge disposed between the first edges of the first honeycomb section and the second honeycomb section, the first honeycomb section, and the first honeycomb section. A lower edge disposed between the second edges of two honeycomb sections, the upper edge and / or the lower edge of the honeycomb seam support being curved. A method for splicing together the honeycomb of claim 11.   15. The method for seaming honeycombs according to claim 14, wherein the first honeycomb side and the second honeycomb side are curved so that the seam forms an arcuate shape.   12. The method for seaming honeycombs according to claim 11, wherein the first honeycomb section and the second honeycomb section comprise acoustic partitions disposed within the honeycomb cells.   The method for splicing together honeycombs according to claim 16, wherein the partition walls comprise partition caps that are adhesively bonded to the walls of the honeycomb cells.   A method for making an engine nacelle comprising seaming together honeycomb sections according to claim 16.   A method for making a jet engine comprising making the engine nacelle of claim 18.   The method for seaming honeycombs according to claim 11, wherein the thickness of the seam is between 0.01 inch and 0.20 inch.

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